It turns out that Steve Kirk had more-or-less forced Stern to give him explicit design credit of his games (something no other designer at that time was accorded), and also to advertise the Pinball Association of America (founder and President, Steve Kirk!) via the stickers.
This caused me to do a bit of research, and track down all the games that Steve Kirk designed (mostly with Stern, but later with Bally/Midway and Williams). I noticed that almost all his games had a little easter-egg on the backglass in the form of his initials and a number (e.g. on Meteor, one of the rockets has SK-5 written on it), implying that these were the numbers of the games he'd designed, in order.
For reference, these games are:
- SK-1: Stars (on the wing of the star-ship)
SK-3: Nineball (on the wizard's hat)
SK-5: Meteor (on the side of one of the rockets heading towards the meteor)
SK-9: Gamatron, a Flight2000 narrow-body conversion kit (on the side of one of the defence-bunker rockets)
SK-13: Ramp Warrior prototype (on the license-plate of the truck)
SK-13: Truck Stop, the production version of Ramp Warrior (now the license plate from the truck on Ramp Warrior is lying on the ground, all crumpled up!)
Here are two interesting interviews with Steve Kirk from 1978 and 1985 in Playmeter (an industry magazine): http://www.backglass.org/stern/steve_kirk_playmeter_4.pdf
I would like to track down PDF copies of the following two issues of PinGame Journal which had articles on Steve Kirk after his death in 2006:
- Issue 119 - December, 2006: Gary Flower remembering pinball designer Steve Kirk who died earlier this year.
Issue 120 - March, 2007: Matt Cianchetti presents an interesting picture of his friend, the late Steve Kirk, explaining Steve's passion for pinball.
There's more trivia about Steve Kirk I could share, so let me know if you're interested.